An endoscope is used to enable a physician to view internal regions of a human or animal body. An endoscope may typically comprise a body, including an elongated tubular distal section adapted for insertion into a patient and a viewing port. Image-transmitting means is provided within the body to transmit an image through the distal section so that the image can be viewed at the viewing port. The field of view can be illuminated in various ways, such as by optical illumination fibers extending through the distal section of the endoscope.
One advantageous way to transmit the image through the distal section is with an image-transmitting rod which may, for example, be constructed of gradient index material. Image-transmitting rods, such as those constructed of gradient index material, tend to be relatively stiff and brittle and may be of very small diameter, such as 0.5 millimeter. Accordingly, image-transmitting rods of this type are subject to breakage by bending forces. An endoscope utilizing an image-transmitting rod, which may be constructed of gradient index material, is shown and described in copending application Ser. No. 909,264 filed on even date herewith entitled Distortion-Corrected Endoscope and naming John Forkner as the sole inventor. This copending application is incorporated by reference herein.
In use of the endoscope, the image-transmitting rod and the distal section of the endoscope are subjected to bending forces. These bending forces may be sufficient to break the image-transmitting rod thereby rendering the endoscope useless for its intended purpose.